Dry cleaning



Feb. 11,1969" Filed June 26, 1964 c. E. M CUTCHEON,

DRY CLEANING Sheet of :3

ii FIGS.

4M, $1.4 mm, aw,

Feb. 11, 1969 c E. MOCUTCHEON, JR 3,426,555

DRY CLEAN I NG 3 of s,

Sheet Filed June 26, 1964' C. E. M CUTCHEON, JR

DRY CLEANING Feb. 11, 1969 Filed June 26,

Sheet Feb. 11, 1969 c. E. M CUTCHEON, JR 3,426,555

' DRY CLEANINQ Filed June 26, 1964 Sheet of 5 FIGB.

MOTOR- 425 RPM.

MOTOR43RP:M.

ACUUM S ITCH VACUUM B AIR BY-PASS United States Patent 3,426,555 DRYCLEANING Charles E. McCutcheon, Jr., Highway and Lucky, Fayette, Mo.65248 Filed June 26, 1964, Ser. No. 378,162 US. C]. 68-12 18 Claims Int.Cl. D06f 33/02 29/02 ABSTRACT OF THE DISCLOSURE and its operation iscontrolled so that a vacuum is drawn in the chamber at the beginning ofthe cleaning cycle and vacuum is maintained in the chamber during thecleaning and drying cycles of operation. Work is cleaned by loading itinto the chamber and sealing the chamber, then drawing a vacuum in thechamber and introducing the evaporative dry cleaning fluid into thechamber. The work is agitated in the chamber and cleaned by the cleaningfluid under a vacuum on the chamber. Then the fluid is drained from thechamber and the fluid evaporated from the work. The used cleaning fluidis reconditioned by a process including the steps of vaporization andcondensation of the fluid.

The invention is especially concerned with a so-called closed-circuitdry cleaning system in which the work is cleaned in a chamber or tubwhich is connected in a closed fluid system adapted to supply a quantityof dry cleaning fluid to the chamber for a cleaning cycle, dischargeused fluid from the chamber after completion of the cleaning cycle, andrecondition the used fluid (i.e., separate therefrom residuals picked upin the cleaning operation) to provide fresh, clean, pure fluid for thenext load. This reconditioning or recovery of the used fluid is carriedout during the drying cycle, which follows the cleaning cycle, and maycontinue for a time after the completion of the drying cycle.

Among the several objects of the invention may be noted the provision ofa system such as described which enables effective and economicalutilization of a modern, fast-acting, odor-free dry cleaning solvent orfluid, such as for example that sold under the trademark Valclene 1 byE. I. du Pont de Nemours & Company of Wilmington, Del. This isunderstood to be a fluid consisting primarily of a fluorocarbon such asthat sold by said company under the trademark Freon 113 plus a smallamount of a detergent. Other fluorocarbon dry cleaning solvents orfluids such as those disclosed in Patent No. 3,042,479 may also be usedin the practice of the present invention. Such dry cleaning solvents orfluids are relatively expensive, and economical utilization thereofnecessitates operation with minimum loss of fluid (which, beingrelatively highly volatile, is relatively difficult to contain) and withsubstantially complete recovery of used fluid. The system of thisinvention enables utilization of such fluid with minimum loss, featuringcleaning of the work under vacuum in a vacuum chamber, as distinguishedfrom cleaning under atmospheric or higher pressure as heretofore. Thistends to preclude the possibility of leakage of fluid from the chamberand inhibits loss of fluid, the tendency being for air to be drawn intothe chamber rather than for fluid or its vapor to escape from 3,426,555Patented Feb. 11, 1969 the chamber. A corollary of this is that indrawing a vacuum in the chamber, vapor is drawn off from the chamber anddelivered into the fluid system for recovery. Among further objects maybe noted the provision of such a system in which the overall cleaningand drying time may be kept to a minimum, drying also occurring undervacuum in the chamber for rapid evaporation of fluid from the work; theprovision of such a system attaining uniform dryness of work on eachcycle and substantially complete evaporation of fluid from the work toavoid loss of fluid; and the provision of such a system attainingsubstantially complete recovery of fluid including recovery of vaporizedfluid entrained in air which may be drawn into the system. Other objectsand features will be in part apparent and in part pointed outhereinafter.

The invention accordingly comprises the constructions and methodshereinafter described, the scope of the invention being indicated in thefollowing claims.

In the accompanying drawings, in which one of various possibleembodiments of the invention is illustrated:

FIG. 1 is a front elevation of a machine of this invention;

FIG. 2 is a rear elevation of the machine;

FIG. 3 is a left side elevation of the machine with a left side panelremoved, taken on line 3-3 of FIG. 1;

FIG. 4 is a right side elevation with a right side panel removed, takenon line 44 of FIG. 1;

FIG. 5 is an enlarged longitudinal cross section of a so-called stripperused in the machine;

FIG. 6 is a diagrammatic flow diagram of the machine;

FIG. 7 is a diagram showing the electric circuitry of the machine; and

FIG. 8 is a time chart showing the sequence of operation during atypical dry cleaning cycle.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

Referring to the drawings, a dry cleaning machine of this invention isshown to comprise a vacuum chamber 1 having a rotary perforated drum orbasket 3 therein for receiving a load of items to be cleaned. Chamber 1may also be referred to as a wash tub (the items or work being washedtherein). Basket 3 may also be referred to as a tumbler, since it isadapted to tumble the 'work. At 5 is indicated a storage tank for drycleaning fluid to be supplied to the chamber or tub 3 for dry cleaningof the work by solvent action. After the work has been cleaned in thetub, the used dry cleaning fluid is discharged from the chamber or tub Iand recovered for subsequent reuse by means of a recovery systemgenerally designated 7 in FIG. 6. The recovery system 7 comprises astill 9 for vaporizing the used dry cleaning fluid, and a series ofcondensers 11, 13 and 15 for condensing the vaporized dry cleaningfluid, the resulting condensed. fluid (the condensate) being ultimatelyreturned to storage tank 5 for reuse. At 17 is indicated a vacuum pumpfor evacuating the chamber or tub I at the start of a cleaning cycle, avacuum being maintained in the chamber during the washing and drying ofwork therein. The discharge side of the vacuum pump 17 (which is ineffect a compressor) is connected to the still & and provides a positivepressure in the still for pressurized delivery of vapor boiling off inthe still through the recovery system 7.

At 19 is indicated a frame which carries the various elements of themachine. The chamber or tub 1 comprises a cylindricalbody mounted inhorizontal position toward the front of the frame, and extending infront-to-rear direction in the frame. It has front and rear end headsconstituted by plates 21 and 23 mounted in the frame. Plate 21 has anaccess opening 25. On the front of the frame is a front panel 2 7 havingan opening 29 aligned with opening 25. A door D is hinged at 30 on panel27 for closing access opening 25. A solenoid-operated latch for the dooris indicated at DL. At DS (see FIGS. 1 and 7) is indicated adoor-actuated switch which is actuated when the door is closed tocomplete a circuit for the door latch DL and for a coin control to bedescribed. At 31 is indicated a lamp which is energized to signal thatthe door is unlatched or open. The door has a gasket 32 engageable withplate 21 around opening 25 with a sufficiently tight seal to preventleakage of air into chamber 1 when the door is closed and while thechamber 1 is under vacuum.

The drum or basket 3 is rotary in chamber 1 on the horizontal axis ofthe chamber, being mounted at its rearward end on the forward end of ashaft 33 which extends through a seal 34 mounted on rear plate 23 of thechamber. Basket 3 has an access opening 35 at its forward end forloading of the work therein and removal of the work therefrom. Itcarries an electrical resistance heating element 37 for heating work inthe basket during the drying of the work, and a thermostatic switch 39for controlling the operation of the latter. Slip rings 37a provide forelectrical connection to the heater 37, and slip rings 39a provide forelectrical connection to the thermostatic switch 39. As shown in FIG. 7,the latter is in series with the coil 41 of a relay which has contacts43 in series with the heater 37. The dry cleaning fluid which it ispreferred to use in the machine has a boiling point of about 11'7-1 18F., and switch 39 is set to close at about 136 F. and to open at about140 F. During the drying cycle, the chamber or tub 1 is under a vacuum,which reduces the solvent boiling point, and thus the clothes are driedby boiling out the solvent at relatively low temperatures.

A pulley 45 is mounted on the rear end of shaft 33 and the pulley andshaft are adapted to be driven alternately by motors 47 and 49. Motor 47is a three-quarter horsepower motor having a shaft 47a projecting fromboth ends. On one end of shaft 47a is a pulley 50 coupled to pulley 45by a belt 51. Motor 47 is adapted to drive shaft 33 at a speed of about425 rpm. via the belt and pulley drive 50, 51, 45 for spindrying. Motor49 is a two-speed one-quarter horsepower motor and is connected by abelt and pulley drive 53 to the other end of shaft 47a of motor 47.Shaft 47a thus acts as a jack shaft in a double speed reduction systemsuch that motor 49 is adapted to drive shaft 33 at a so-called tumblespeed of about 43 rpm. or a so-called distribution speed of about 63rpm. When motor 47 is operating, a clutch (not shown) uncouples themotor 49 from the double reduction system.

The storage tank for the dry cleaning fluid has a partition 55 (see FIG.6) which divides it into a so-called wash solvent section 57 and aso-called storage section 59. The wash solvent section 57 receivescondensed dry cleaning fluid (solvent) from the condenser 11. This fluidmay contain some water. The water, being lighter than the dry cleaningfluid, will float on top of the latter in section 57. As section 57becomes filled, the water at the top and some of the dry cleaning fluidspills over the top of the partition 55 into section 59 of the tank.Thus, a substantially waterfree supply of dry cleaning fluid is providedin section 57. Section 57 holds about thirteen gallons of fluid, forexample, and approximately eleven gallons, for example, are dischargedduring a cleaning cycle. The fluid is adapted to flow by gravity fromsection 57 of tank 5 through a conduit 61 to the chamber 1. A washsolvent solenoid valve 63 in conduit 61 controls flow of fluid from tanksection 57 to the chamber.

In the course of operation of the machine, used dry cleaning fluid isdischarged from chamber 1 to still 9. During this phase of operation, asolenoid valve 65 below storage tank 5 opens to equalize the level offluid in sections 57 and 59 of the tank. This equalization of the fluidlevels insures that sufiicient fluid will be available in section 57,after distillation and condensation of the used dry cleaning fluid, toprovide a copious overflow of solvent across the partition between thetwo sections, thereby transferring water collected in section 57 over tosection 59. A manual drain valve 67 provided for section 59 of the tank5 is periodically opened to remove the water from section 59 (some drycleaning fluid may also be removed at this time). Such dry cleaningfluid as may be removed from section 59 can be transferred to the still9 and distilled therein for recovery.

A float assembly 69 in tank 5 comprises a magnetic float 71 and lowerand upper reed switches 73 and 75, respectively. Switch 73 is normallyclosed and opens when the level of fluid in section 57 of the tank dropsand the floating magnet comes into proximity with the switch. Switch 73is in series with the solenoid valve 63 and deenergizes the solenoidwhen the level in the storage tank drops to a predetermined level, suchas about two inches above the bottom of the tank. The upper switch 75 isnormally open and closes when the storage tank solvent level rises insection 57 and the float 71 rises. FIG. 6 shows section 57 full andswitch 75 closed. Switch 75 opens if the level of fluid in section 57falls below that required for a cycle, and takes the machine temporarilyout of service until an adequate supply of fluid transfers from thestill to the storage tank. Switch 75 is closed at the start of anyoperation of the still 9 during (and after) the previous cycle.

The suction inlet of vacuum pump 17 is in communication with chamber 1via a conduit 77 having a filter 79 therein. A vacuum gauge 81 may beprovided for reading the vacuum drawn in the chamber. The pump 17 is aconventional refrigeration compressor, for example, capable of drawing avacuum of at least 28 inches of mercury in the chamber 1 .and having adischarge pressure of about 10 p.s.i. Operation of the pump 17simultaneously produces a vacuum in chamber 1 and a pressure downstreamfrom the pump in the recovery system 7, this pressure being utilized totransfer vapors from still 9 through the recovery system as explainedhereinafter.

The discharge outlet of pump 17 is connected by a conduit 83 to thestill 9, a pressure relief valve 85 being provided in conduit 83 tolimit pressure entering the still to a maximum of 10 p.s.i. An airby-pass solenoid valve 87 in a conduit 89 branching from conduit 83 isopen during initial operation of pump 17 at the start of a dry cleaningcycle, s that residual air or other gases in chamber 1 which do notcontain dry cleaning fluid to be reclaimed are discharged directly tothe .atmosphere. Valve 87 is closed during recovery of used dry cleaningfluid and opens again at the end of the drying cycle. A gauge 91 may beprovided for indicating the outlet pressure of the pump 17.

The chamber or tub I is connected to still 9 by a drain line 93 having asolenoid-operated dump valve 95 therein. This valve is opened at the endof the wash phase of a cycle to discharge used dry cleaning fluid fromthe chamber to the still. Fluid in the still 9 is heated by hot waterflowing through a heating coil 97 therein. The ends of the heating coil97 project through a rear clean-out door 99 (see FIG. 2) and areconnected to a suitable source of hot water (not shown). A hot watercirculating pump 100 (see FIG. 6) may be provided for circulating thehot water. The clean-out door 99 and the coil 97 are periodicallyremoved for removal of dirt, detergent, etc. which collects in thestill. A manually operated drain valve 101 is provided for draining thestill. A solenoid valve 103 is provided for starting and stopping theflow of hot water through the coil.

Since the vacuum pump 17 reduces the pressure in chamber 1 belowatmospheric pressure, and since the discharge outlet of the vacuum pumpis connected to the still 9, there is a pressure differential betweenthe still and the chamber during the cycle. This pressure differentialneeds to equalize before opening of the dump valve 95 to prevent entryof gases from still 9 into the chamber through the dry cleaning fluid inthe bottom of the chamber. For this purpose, there is provided apressure equalizer conduit 105 between the still and the chamberconnected to the latter above the level of the dry cleaning fluidtherein, this conduit having a solenoid valve 107 therein. Valve 107 isopened to equalize pressure between the still and the chamber prior toopening of the valve 95 to dump used dry cleaning fluid into the still.A pressure-responsive safety valve 109 is provided to prevent excessivebuild-up of pressure in the still.

Since the chamber or tub I is under a vacuum during the drying cycle, itmust be returned to atmospheric pressure before door D can be opened.For this purpose, a solenoid operated vacuum breaker valve 111 isconnected to the top of the chamber, this valve being opened at the endof the drying phase of the cycle to permit atmospheric air to enter thechamber, thus breaking the vacuum in the chamber, and permitting thedoor 25 to be opened.

At 113 is indicated an exhaust solenoid valve 113 for the chamber ortub 1. This is controlled by a doublethrow door-actuated switch 115,(see FIG. 7), this switch closing to solenoid valve 113 when the door Dis opened and closing to a control box generally designated B in FIG. 7when the door is closed. An exhaust blower or fan 117 connected to theoutlet of valve 113 pulls out gases from the chamber 1 when the valve isopen. The blower 117 is energized along with valve 113 by operation ofthe door switch 115. Thus, when the door D is opened, air is circulatedthrough the chamber 1 and residual gases in the chamber are evacuatedthrough the opened valve 113.

During each wash cycle, detergent from a supply tank 1.19 is supplied tochamber 1 via a line 121 having a solenoid valve 123 therein. Thechamber is under a vacuum at the time the detergent is supplied, and thedetergent supply tank 119 may be located below the chamber and thedetergent siphoned through the line 121. The detergent in supply tank119 can be a detergent-solvent mixture sold under the name Valclene 200by E. I. du Pont de Nemours & Company which is understood to consist ofapproximately 80% Freon-type solvent and 20% detergent. About two fluidounces of this mixture are supplied during each wash cycle. Thedetergent in the detergent-solvent mixture is either retained to someextent on the work or is deposited in the still 9 during distillation ofthe used dry cleaning fluid.

Two vacuum switches 125 and 127 are provided in communication with thechamber or tub 1. Switch 125 is a safety switch for preventing operationof the system at less than a predetermined vacuum, being open whenvacuum in the chamber is below four inches of mercury, for example, andclosed when the vacuum increases to approximately eight inches ofmercury, for example. Switch 125 is connected in a circuit with thevacuum pump 17 as explained hereinafter so that the pump is energizedwhen the vacuum drops below four inches of mercury. The vacuum switch127 functions as a dry sensor, in a manner to be hereinafter explained,to prolong the drying phase of the cycle, if necessary, and to insurethat each work load is uniformly dried.

Vaporized dry cleaning fluid (and possibly other fluids) vaporized instill 9 are delivered to condenser 11 via a conduit 128 having a manualcontrol valve 129 therein. The vapors passing through the condenser 11are at greater than atmospheric pressure. The condenser 11 is awater-cooled tube-in-tube condenser, for example, cooled by cold waterpassing through a tube 130 under control of a manual valve 131. Positivepressure in still 9 forces the condensed fluid through the condenser 11and into section 57 of the storage tank 5.

All the vapor may not be condensed in condenser 11 and air saturatedwith vapor may enter tank 5. This flows via a conduit 133 to a so-calledaccumulator tank 135 and to the condenser 13 (which is a refrigeratedcondenser). The accumulator tank 135 floats on conduit 133, that is, itreceives saturated air from the storage tank 5 and discharges it inresponse to pressure conditions in the conduit 133. As pressure inconduit 133 increases due to operation of the pump 17 and the slowpassage of fluids through refrigerated condenser 13, the pressureincreases in conduit 133 to force the saturated air into the accumulatortank 135. As the vapors u1timately pass through refrigerated condenser13, the pressure downstream from the accumulator tank decreases, andsaturated air exits from the accumulator tank and enters the condenser13. A normally closed pressure switch 136 in communication with theaccumulator tank opens if the pressure therein exceeds four p.s.i. todeenergize the pump 17 as explained later.

Condenser 13 includes two parallel-connected condenser coils 137 and 139through which the saturated air passes. The vapor in coils 137 and 139is cooled by heat-exchange with a refrigerant line 1141 supplied withrefrigerant from a refrigeration system including a compressor 145, acondenser 147, a receiver 148 and a themostatic expansion valve 149. Thevalve 149 is controlled by a thermostat 151. The refrigerant system isadapted to be defrosted by opening a defrost solenoid valve 153 todeliver hot refrigerant to the cooling coils.

As the saturated air passes through the coils 137 and 139, vapor in theair is condensed and drains through a conduit 155 into a collector 157.A branch conduit 159 connects conduit 155 with the vapor inlet of thecondenser 15, which is also refrigerant-cooled and which may be called astripper. Vapor remaining in the air is condensed in the stripper, inwhich the air flows upward around a finned portion 161 of refrigerantline 141. Condensate drains from stripper 15 through a line 165 into thecollector 1.57. The remaining air, containing at most a minor amount ofvapor, passes upward from the stripper through a conduit 167 havingtherein a check valve 169 for preventing back flow of air into thestripper and a throttle valve 171 for restricting the passage of airfrom the stripper through the conduit to the atmosphere. Valve 171 alsoregulates the output of air from the accumulator 135 since it determinesthe volume of gas which can pass through the coils 137, 139. Somesolvent may condense downstream from the valve 171, and any suchcondensate is collected in a jar 173. Collector 157 is connected to thestill 9 by a conduit 175 having a solenoid operated valve 177 thereinwhich opens when the dump valve 95 is energized thereby to draincondensate in the collector 157 into the still.

As herein illustrated, the machine is coin-controlled, the control box Bbeing a commercially available coin accumulator control meter, such asthe Series 5800 Deal- A-Price Coin Accumulator Meter sold by H.Greenwald Company of Brooklyn, NY. Generally, this meter comprises aso-called start switch 181 (which is a doublethrow switch), a stepperswitch 183 operated by a stepper coil 184, a so-called homing and bypassswitch 185, and a so-called coin bypass switch 186 (see FIG. 7).Associated with the meter is a so-called rejector assembly 187 (see FIG.7) which includes a coin-actuated switch 189 and a rejector coil 191.

Switch 181 is normally closed on its lower contact as shown in FIG. 7,switch 183 is normally open, and switch is normally closed on itsright-hand contact. Switch 189 is normally closed on its upper contact.When a coin is inserted in the meter, switch 189 closes momentarily onits lower contact, sending a pulse of current through stepper coil 184via switch 75 (which will be closed assuming the level of fluid instorage tank section 57 is up), a manual switch 193 and a manual switch195. On the first such pulse, switch 185 closes on its left-handcontact. Upon insertion of the proper amount in coin (as set up in themeter), start switch 181 closes on its upper contact, and thisinstitutes a cycle of the machine.

Switch 193 may be manually opened for placing the machine out ofservice. A signal lamp 197 may be provided paralleling switches 75 and193 for signalling an open condition of either of these switches,indicating that the machine is out of service. Switch 195 is a defrostswitch for the refrigeration system of the machine, adapted to be openedoff two upper contacts and closed on a lower contact for this purpose. Asignal lamp 199 may be provied paralleling switch 195 for signallingthat switch 195 has been thrown for defrosting and that the machine isout of service.

Referring to FIG. 7, electric power supply lines for the machine areindicated at L1 and L2. The motor of refrigerant compressor 145 isconnected directly across these lines, and hence is energizedcontinuously as long as lines L1 and L2 are plugged into a serviceoutlet and energized.

A sequence timer or programmer switch unit is indicated generally at Pin FIG. 7. This is of a conventional type including a plurality ofswitches actuated by cams on a camshaft driven by a timer motor. Thecams and camshaft are omitted from the drawings; the timer motor isindicated at 201 in FIG. 7. Programmer P is shown to comprise tendouble-throw switches S1S10, each having a movable contactor adapted toclose from a neutral position on a top contact T or a bottom contact B.Motor 201 is connected between the top contact of switch S and line L1.The movable contactors of switches S1S7, S9 and S10 are electricallyinterconnected as shown in FIG. 7. The movable contactor of switch S8 isinterconnected with the power line for compressor 145 so that current issupplied thereto as long as supply lines L1 and L2 are live. Switch S8controls heating of the still 9, and operation of the still may continueafter termination of a cleaning and drying cycle of the machine.

The motor 201 drives the switchactuating cams of programmer P through360 during each cycle of operation of the machine to control thesequence of steps in the dry cleaning process. It rotates the camsapproximately 8 during each of forty-five 22 /2 second intervals for approximately a seventeen minute dry cleaning cycle. A circuit is closedto the timer motor 201 through upper contact T of switch S10 exceptduring the dry sensor operation explained later. The time chart of FIG.8 shows the closure condition of switches S1S10 on the top T or bottom Bcontacts of the switches during the respective forty-five 22 second timeintervals.

As charted in FIG. 8, the cam for programmer switch S1 is such as tohold the switch closed on its top contact T for the first 22 /2 secondinterval, and to close switch S1 011 its bottom contact B for theremaining forty-four 22 /2 second intervals, the switch closing back onits top contact at the termination of the complete time cycle.

The cam for switch S2 is such as to hold this switch open for the firstsixteen intervals, to close it on its bottom contact at the beginning ofthe seventeenth interval and hold it closed on the bottom contactthrough the twentieth interval, to hold it open for the twenty-firstinterval, to close it on its top contact at the beginning of thetwenty-second interval and hold it closed through the forty-secondinterval, then open it for the remainder of the time cycle.

The sequence for the remainder of the switches will be apparent from thechart.

As noted, switch S1 is closed on its top contact T at the start of acycle of the machine. The circuitry is such as shown in FIG. 7 that,upon closure of start switch 181 on its upper contact, current issupplied via switch 181 to the top contact of switch S1. The movablecontactor of switch S1 is connected to the movable contactor of switchS10, which is closed on its upper contact, and the latter isinterconnected with timer motor 201. Accordingly, upon closure of startswitch 181 on its upper contact, motor 201 is energized and startstiming out the sequence of the machine. At the end of the first 22 /2second time interval, switch S1 closes on its bottom contact B, which issupplied directly with current from line L2. This holds motor 201 inoperation.

Switch S3 is closed on its bottom contact at the start of a cycle. Bothtop and bottom contacts of this switch are interconnected with motor 49.With S3 closed on its bottom contact, motor 49 is energized foroperation at low speed to drive basket 3 at approximately 43 rpm.

The accumulator tank pressure switch 136 (shown at the bottom of FIG. 7)is connected in series with the coil of a defrost relay R1 across linesL1 and L2. Switch 136 is normally closed at the beginning of each cyclesince the pressure in the accumulator tank 135 is less than 4 p.s.i.Thus, the coil of relay R1 is energized to close the associated normallyopen relay contacts RlA and open the normally closed relay contacts RIBof relay R1. Switch S7 is closed on its top contact T during the firsttime interval to complete a circuit through the defrost relay contactsR1A to the coil of a vacuum pump relay R2. This closes the normally openrelay contacts RZA and RZB to close a circuit to the vacuum pump 17between lines L1 and L2.

A thermal reset relay R3 has normally open contacts R3A in parallel witha push button switch 203. The relay contacts R3A and switch 203 areinterconnected with two thermostatic switches TH1 and TH2 which sensethe temperature in the storage tank '5 and in the conduit 93 betweenchamber 1 and still 9. The thermostatic switches TH1 and TH2 arenormally closed and, by closing the push :button switch 203, the coil ofrelay R3 is energized and contacts R3A close to hold the circuit closeduntil the thermostatic switches open. Opening of either of thethermostatic switches places a signal lamp 205 in the circuit,indicating that the circuit is open. The thermal reset relay R3 hasanother normally open set of contacts R3B in series with the bottomcontact of switch S8. A normally closed hot water switch 207 is inseries with the relay contacts R3B, a normally closed water pressureswitch 209 and hot water solenoid valve 103. During the first timeinterval of the dry cleaning cycle, as well as between dry cleaningcycles, current is provided through the lower contact of switch S8,through the relay contacts R3B, and switches 207 and 209 to the hotwater solenoid 103 to open the valve and permit hot water to flowthrough the coils 97 in the still.

Switch S9 is closed on its bottom contact during the first two timeintervals of operation of the timing motor to close a circuit to the airbypass solenoid valve 87 downstream of the vacuum pump 17 so that airand other gases initially pumped from chamber 1 are discharged to theatmosphere. At the end of the first time interval, switch S1 closes onits bottom contact so that line current is received directly by theprogrammer P. Simultaneously, switch S8 is opened to its neutralposition to take the hot water solenoid valve 103 out of the circuit,thereby closing the valve and stopping circulation of hot water in thestill. When vacuum in chamber 1 is greater than 4 inches of mercury,vacuum switch closes and this places the coil of a vacuum relay R4 in acircuit from the bottom of the programmer P. The vacuum relay R4 has aset of normally closed contacts R4A in a circuit to the bottom contactof switch S4. A normally open set of contacts R413 of relay R4 is in acircuit to the bottom contact of switch S6.

At the beginning of the third time interval and when vacuum relaycontacts R4B are closed, a circuit is com.- pleted from the bottomcontact of switch S6 through the normally closed magnetic fill switch 73in tank 5 and the solenoid fill valve 63, so that dry cleaning fluid istransferred from tank 5 to tub 3. A spark suppressor circuit consistingof a 510 ohm resistor 210 and a 0.1 mfd. capacitor 212 is in parallelwith the magnetic switch 73. As long as vacuum is retained in chamber 1,vacuum switch 125 remains closed and relay R4 is energized so that thesolenoid valve for filling the chamber can be opened. Should there beleakage into the chamber which prevents its evacuation, switch 125 willnot close and dry cleaning fiuid will not be supplied to the chamher.This prevents loss of expensive dry cleaning fluid by evaporation from aleaking chamber. During the third time interval, switch S4 is closed onits bottom contact, but a circuit including this contact is not completewhen the chamber has been evacuated, since the relay contacts R 4A arethen opened. Should the vacuum in chamber 1 be reduced or lostaltogether, switch 125 opens, relay R4 is deenergized and contact R4Areturns to its normal closed position. This completes a circuit to therelay R2 to start the vacuum pump. Thus, operation of the relay R4 andits contacts prevents the vacuum in chamber 1 from dropping below 4inches of mercury any time switch S4 is closed on its bottom contact.

At the beginning of the third time interval in the cycle, switch S9takes the air bypass solenoid valve 87 out of the circuit to close thevalve so that any vapor evacuated from chamber 1 by the vacuum pump 17is directed to the still 9. This prevents evacuation of dry cleaningsolvent vapors from the system.

Switch S7 is closed on its bottom contact at the beginning of the thirdtime interval to close a circuit through the programmer P and thedefrost switch 195 to the refrigeration solenoid defrost valve 153 whichdirects hot refrigerant gases through the refrigeration system fordefrost purposes.

Starting with the sixth time interval, switch S8 is closed on its topcontact for two increments to energize the detergent solenoid valve 123and provide detergent to the chamber 1. The switch S8 is opened at theend of the seventh time interval to close the valve 123.

At the start of the tenth time interval, switch S6 closes on its topcontact to close a circuit to the solenoidoperaed equalizer valve 107between chamber 1 and still 9 to equalize the pressure therebetween. Atthe end of the tenth time interval, switch S4 opens to take the relay R2out of the circuit. At the end of the eleventh time interval, switch S7opens to terminate the refrigerator defrost cycle. Also at the end ofthe eleventh interval, switch S5 closes on its bottom contact, whichsimultaneously operates the dumping solenoid valve 95, the storage tankequalizing valve 65 and the collector drain valve 177. This dischargesthe used dry cleaning fluid from chamber 1 into the still 9 andequalizes the level of fluid in the sections 57 and 59 of the storagetank. Also, any dry cleaning fluid in collector tank 157 from theprevious cycle is discharged into the still 9.

At the start of the fifteenth time interval, switch S3 closes on its topcontact to close a circuit to motor 49 and increase the speed of thebasket 31 to approximately 63 r.p.m., i.e., its distribution speed. Atthe start of the seventeenth time interval the swich S2 closes on itsbottom contact B to energize the high speed motor 47 to turn the basket3 at approximately 425 rpm. until the end of the twentieth timeinterval. This high speed spin of the basket extracts most of the drycleaning solvent from the articles in the basket. The solvent drains tothe bottom of the chamber 1 and into the still since the dump valveremains open through the twenty-first time interval. There is a pause inthe rotation of the basket during the twenty-first interval, and at theend of the twenty-first interval switch S5 moves to its neutral positionto close the dump valve 95, and simultaneously the switch 86 moves toits neutral position to close the equalizer valve 107.

The drying and distillation cycle of the machine starts with thetwenty-second time increment. Switch S2 closes on its top contact, whichsupplies current to a transformer T1 to energize the heater relay 41.This closes the heater relay contacts 43 to close the circuit to theheater 35. At the same time a machine cycle counter CTR connected acrossthe secondary winding of the transformer is advanced. Simultaneously,switch S3 closes on its bottom contact again to operate motor 49 at itslow speed to turn basket 3 at approximately 43 rpm. Switch S7 closes onits top contact again to start the vacuum pump 17 to evacuate chamber 1.The vacuum pump continues to operate through the forty-fourth timeinterval and maintains a vacuum in the chamber during the drying cycle.The vacuum in the chamber causes the evaporative dry cleaning fluid toboil and rapidly evaporate, thereby substantially reducing the overalldrying cycle time. Operation of the heater 35 prevents the evaporativedry cleaning fluid from freezing in chamber 1 during the drying cycle asa result of rapid evaporation. Also at the beginning of thetwenty-second time interval, switch S8 closes on its bottom contactagain to energize the hot water solenoid 103 so that hot water iscirculated through the coil 97 in still 9 to vaporize dry cleaning fluidand other liquids therein. The motor 47 is periodically switched fromits low to high speed during the drying cycle as indicated in the FIG. 8chart to prevent the work from adhering to the basket.

At the beginning of the thirty-sixth time interval, switch S10 opens totake the timer motor 201 out of the circuit. All ten switches 81-810 ofthe sequence timer switch 199 then remain in status quo until such timeas the vacuum switch 127 closes to energize the timer motor 201 therebyto continue the sequential operation of the switches. Switch 127 isnormally open and the timer motor is by passed until such time as thevacuum required to close switch 127 is reached in chamber 1. As long asthe work is moist and emitting vaporized dry cleaning fluid in thechamber, the vacuum in the chamber does not increase suificiently toclose switch 127. Only when the work is dried does the vacuum increasesufficiently to close switch 127. Thus, switch 127 is a dry sensor, andassures removal of articles from the dry cleaning machine at a uniformdryness. In the event switch 127 closes prior to the time that switchS10 opens, then the motor 201 continues to run without interruption andthe machine continues its normal sequential operation. Operation of drysensor switch 127 only prolongs the drying cycle of the machine untilsuch time as the clothes have been dried. When the switch 127 energizesmotor 201, and the thirty-seventh time interval is reached, switch S10closes on its top contact and energizes the timer motor throughout thebalance of the cycle.

At the end of the forty-second time interval, switch 82 opens to takerelay 41 out of the circuit, thereby opening the circuit to the heater35 to terminate heating in tub 3. At the beginning of the forty-thirdtime interval switch S5 closes on its top contact to close the circuitto the vacuum break valve 111, which returns chamber 1 to atmosphericpressure. This valve remains open until the end of the dry cleaningcycle.

At the start of the forty-fourth time interval, switch S9 closes on itsbottom contact, to open the air bypass valve '87 so that the gases beingpumped by the vacuum pump 17 from chamber 1 are discharged to theatmosphere. The vacuum pump stops operating at the end of theforty-fourth time interval when switch S7 closes on its top contact tode-energize relay R2. During the final time interval of the cycle,switch S4 closes on its top contact, which operates the mechanism in themeter B to reset it and prepare the machine for the next cycle ofoperation.

Operation of the machine is as follows:

Work to be cleaned is loaded in basket 3, and door D V is closed,thereby closing switch DS to the solenoid-operated door lock DL andclosing switch to the coin meter B while simultaneously opening thecircuit to the blower 117 and valve 113. Coins are then inserted toenergize stepper coil 184 via coin switch 189 to throw the homing andbypass switch 185 and power start switch 181 over from their FIG. 7initial position. This closes the circuit to programmer P, and switch S3starts the motor 49 to rotate basket 3 at tumble speed to tumble thework in the basket. Simultaneously, switch S7 closes to start the vacuumpump 17 which evacuates air or other gases from the chamber or tub 1.The gases are discharged 1 1 to the atmosphere through the valwe 87which was opened by switch S9. Hot water is directed through the coil 97in the still during the initial time interval. The timer motor isstarted by switch S10.

The vacuum pump operates for the first two time intervals, producingapproximately 20 inches of vacuum in the chamber 1. The vacuum pump thenstops and air bypass valve 87 closes. Switch S6 opens fill valve 63 todeliver about eleven gallons of dry cleaning solvent from section 57 oftank to chamber 1 during the third to the sixth time intervals of thecycle. Air from the accumulator tank 135 prevents vapor lock in thesolvent tank. Delivery of the solvent tochamber 1 reduces the vacuumtherein to about 7 inches of mercury. About two fluid ounces ofdetergent from tank 119 is supplied to chamber 1 during intervals sixand seven of the wash cycle by operation of switch S8. Switch S7 opensthe defrost valve at the third time interval and the refrigerated coilsof condenser 13 are defrosted for nine increments of the cycle.

At the tenth interval, switch S6 opens the equalizer valve 107 andpressure between chamber 1 and still 9 is equalized. The dump valve 95is open from the twelfth through the twenty-first intervals and used drycleaning fluid is discharged from tub 3 into still 9. This furtherreduces the vacuum in the tub to about 5 inches of mercury. While thedump valve is open the basket 31 is turned at its tumble speed of 43rpm, then at its distribution speed of 63 rpm, and finally at itsextraction speed of 425 rpm. to extract as much as possible of theliquid solvent from the clothes, such being drained from chamber 1 intothe still. The basket 31 pauses during the twentyfirst increment.

The dump and equalizer valves 95 and 107 close at the end of thetwenty-first inter-val and the vacuum pump again commences operation.Simultaneously hot water begins circulating through the still coils 97for vaporizing fluids in the still. The motor 49 starts and turns basket31 at speeds of 43 and 63 rpm, the tumbling and distribution speeds,respectively. Switch S2 starts the heater 37 to heat the clothes inbasket 31 and boil off the dry cleaning fluid. As the pressure inchamber 1 is lowered by the vacuum pump, the boiling point of the liquiddry cleaning fluid is lowered and this, together with the heat suppliedby heater 37, results in rapid evaporation of dry cleaning fluid in thechamber. As the dry cleaning fluid is vaporized, the vacuum in thechamber is increased from about 12 inches of mercury at time intervaltwenty-one to about 27 inches of mercury at interval thirty-five.

The timer motor 201 is taken out of the circuit by switch S10 during thethirty-sixth time interval so that the drying cycle continues until thevacuum increases to about 28 inches of mercury and switch 127 closes.When this occurs, the timer motor 201 starts and again controls the drycleaning cycle. After the forty-second time interval, the clothes aredry and vacuum break valve 111 opens and air enters chamber 1. One timeinterval later the air bypass valve 87 opens and air is discharged fromvacuum pump 17 to the atmosphere. After the forty-fourth time interval,switch S7 opens to stop the vacuum pump and end the dry cleaning cycle.The door D can then be opened and the work removed from the basket.Blower valve 113 opens and blower 117 starts when the door opens toassure removal of residual gases in the chamber 1.

At the beginning of the drying cycle (interval twentytwo) hot waterbegins circulating through still 9 and vaporizes the dry cleaning fluid.The pressure in the still from operation of vacuum pump 17 andevaporization in the still moves the vaporized fluid through the conduit12.5 to the condenser .11. Cool water in condenser 11 condenses a largeportion of the vaporized dry cleaning fluid which is then returned tosection 57 of tank 5. A portion of the dry cleaning fluid in tank 5,including any water condensed in condenser 11, is transferred overpartition 55 into section 59 and eventually removed from the storagetank.

The vapors remaining are transferred through line 133 to the accumulatortank 135 and ultimately to the refrigerated condenser 13. Therefrigerated condenser 13 condenses even more of the vaporized drycleaning fluid and transfers the condensate through the line to thecollector 157. The remaining gas is primarily air and it is transferredthrough the line 159 into the refrigerated stripper 15 wheresubstantially all of the remaining dry cleaning solvent is condensed anddischarged into the collector 157. The remaining gases pass through thecheck valve 169 and the control orifice or valve 171 to the atmosphere.The dry cleaning fluid collected in collector 157 is transferred tostill 9 during the twelfth to the twenty-first time intervals of thenext cycle.

It is to be noted that vacuum is drawn in chamber or tub 1 throughoutthe cycle. This means that if there is any leakage as regards chamber ortub .1, it is leakage of air into the chamber rather than leakage of drycleaning fluid out of the chamber, this air being passed through therecovery system and discharged to atmosphere from stripper 15. Ifchamber 1 were at atmospheric pressure or higher than atmosphericpressure during the cycle, any leakage (such as leakage through theshaft seal 34 as may occur) would result in loss of dry cleaning fluid.The latter is relatively expensive, and for economical operation it isimportant that loss of fluid be avoided, and that substantially allfluid used in the chamber 1 be recovered. The machine and method of thisinvention accomplish this. Use of the vacuum pump 17 greatly facilitatesdrying of the work and substantially reduces the time cycle. A drycleaning machine of this invention using a Freon solvent can be operatedon a cycle of about 12 to 16 minutes as compared to the usual 45 minutesfor present dry cleaning machines using conventional dry cleaningsolvents. This reduction in the cycle time affords a substantialeconomic advantage to the coin operated installation and to theprofessional dry cleaner.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions and methodswithout departing from the scope of the invention, it is intended thatall matter contained in. the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

What is claimed is:

1. A dry cleaning machine comprising a vacuum chamber for receiving workto be cleaned and then dried, means for effecting agitation of work insaid chamber during a cleaning cycle and a subsequent drying cycle, aclosedcircuit fluid system for said chamber comprising means forsupplying a quantity of evaporative dry cleaning fluid to said chamberfor cleaning of the work, discharging used fluid from the chamber uponthe termination of a cleaning cycle, and reconditioning the fluid forreuse, and vacuum means in communication with the chamber for drawing avacuum in said chamber for cleaning and drying of the work under vacuumin the chamber, said vacuum means being in communication with thechamber above the level of fluid therein, and said vacuum meanscomprising a vacuum pump having its inlet connected to the chamber andits outlet connected to the closed-circuit system for pressurizing thelatter.

2. A dry cleaning machine as set forth in claim 1 wherein the fluidsystem comprises a storage tank for the fluid, means for receiving usedfluid from the chamber and vaporizing the fluid, and means forcondensing the vaporized fluid and delivering the condensate to thestorage tank.

3. A dry cleaning machine as set forth in claim 2 wherein saidvaporizing means comprises a still and means for circulating hot waterthrough the still in heat-exchange relation to fluid in the still, andsaid condensing means comprises means for circulating a coolant inheat-exchange relation with vapor delivered from the still.

4. A dry cleaning machine as set forth in claim 3 wherein the vacuumpump has its outlet connected to the still for pressurizing the still.

5. A dry cleaning machine as set forth in claim 3 further comprisingmeans for equalizing pressure between the chamber and the still forenabling discharge of fluid from the chamber to the still.

6. A dry cleaning machine as set forth in claim 5 further comprisingmeans for breaking the vacuum in the chamber at the completion of thedrying cycle.

7. A dry cleaning machine as set forth in claim 3 wherein saidcondensing means comprises first condensers, a primary condenser forreceiving vapors from the still and delivering the resultant condensateto the storage tank and auxiliary condensing means for condensing vaporentrained in air delivered from the storage tank and delivering theresultant condensate to a collector, and means for returning condensatefrom said collector to the still.

8. A dry cleaning machine as set forth in claim 7 wherein said auxiliarycondensing means has an air outlet in restricted communication with theatmosphere.

9. A dry cleaning machine as set forth in claim 7 wherein the primarycondenser is water-cooled, and said auxiliary condensing means comprisesa refrigerant-cooled condenser converted to said collector, and arefrigerant-cooled stripper also connected to said collector and havingan air outlet in restricted communication with the atmosphere.

It A dry cleaning machine as set forth in claim 8 having a vaporaccumulator in communication with said storage tank and said auxiliarycondensing means.

11. A dry cleaning machine comprising a vacuum chamber; a door for saidchamber; a rotary basket in said chamber adapted for reception of workto be cleaned and dried and unloading of finished work via said door; aclosed-circuit fluid system for said chamber comprising a storage tankfor dry cleaning fluid, means for delivering a quantit or" fluid fromthe storage tank to the chamber for a cleaning cycle, a still connectedto said chamber for receiving used fluid from the chamber after acleaning cycle and vaporizing the fluid, and means for condensingvaporized fluid from the still and returning the resultant condensate tothe storage tank, a vacuum pump having its inlet connected to thechamber and its outlet connected to the still, said pump being adaptedto draw a vacuum in the chamber for cleaning and drying of work undervacuum in the chamber and to pressurize the still for pressurizeddischarge of vapor from the still, and means for programming a cycle ofthe machine comprising operation of the pump to draw a vacuum in thechamber, delivery of fluid from the storage tank to the chamber,rotation of the basket for cleaning the work under vacuum in thechamber, followed by discharge of fluid from the chamber to the still,and rotation of the basket for drying the work under vacuum in thechamber.

12. A dry cleaning machine as set forth in claim 11 wherein saidprogramming means includes a timer, and said machine includes means forsensing dryness of work being dried in the chamber and controlling saidtimer to control the length of the drying cycle of the machine.

13. A dry cleaning machine as set forth in claim 12 wherein said sensingmeans comprises a switch responsive to the degree of vacuum in thechamber and controlling the timer.

14. A dry cleaning machine as set forth in claim 11 wherein said storagetank is a closed tank, wherein said condensing means comprises a primarycondenser in said fluid system between the still and the tank, andauxiliary condenser means in said fluid system for condensing vaporsdischarged from said storage tank, an accumulator connected into saidsystem between said storage tank and said secondary condenser means, acollector for collecting condensate from said auxiliary condensor means,and means for delivering condensate from said collector to the still.

15. A dry cleaning machine comprising a vacuum chamber; a door for saidchamber; a rotary basket in said chamber adapted for reception of workto be cleaned and dried and unloading of finished work via said door, aclosed-circuit fluid system for said chamber comprising a storage tankfor dry cleaning fluid, a fluid connection between said tank and chamberhaving a fill valve therein, a still, a fluid connection between saidchamber and the still having a dump valve therein, and means forcondensing vaporized fluid from the still and returning the resultantcondensate to the tank, a vacuum pump having its inlet connected to thechamber and its outlet connected to the still, said pump being adaptedto draw a vacuum in the chamber for cleaning and drying of work undervacuum in the chamber and to pressurize the still for pressurizeddischarge of vapor from the still, means including an equalizer valvefor equalizing pressure in the chamber and the still, means including avent valve for venting the tank to atmosphere, means for programming acleaning cycle of the machine followed by a drying cycle with thecleaning cycle comprising operation of the pump to draw a vacuum in thechamber, rotation of the basket, opening of the fill valve for deliveryof fluid from the storage tank to the chamber for cleaning of the Workby said fluid, followed by opening of said equalizer valve forequalizing pressure in the chamber and still, opening of the dump valvefor draining used fluid from the chamber into the still, closure of theequalizer valve and the dump valve, drying of the work under vacuum inthe chamber, and opening of the vent valve: for venting the chamber toatmosphere.

16. A dry cleaning machine as set forth in claim 15 wherein saidprogramming means includes means for starting said pump at the start ofa cleaning cycle, stopping it during the filling of the chamber and theremainder of the cleaning cycle, restarting it for the drying cycle, andstopping it toward the end of the drying cycle.

17. A dry cleaning machine as set forth in claim 16 wherein saidprogramming means includes a timer motor, and means for stopping saidtimer motor at a predetermined point in the drying cycle, and whereinthere is provided means for sensing dryness of work in the chamber andrestarting said timer motor in response to said sensing mean forcontrolling the length of said drying cycle.

18. A dry cleaning machine as set forth in claim 17 wherein said sensingmeans comprises a switch responsive to the degree of vacuum in thechamber and acting to restart the timer motor when the pump has drawn apredetermined degree of vacuum in the chamber corresponding to apredetermined dryness factor of the work.

References Cited UNITED STATES PATENTS 2,126,426 8/1938 Traube 6820 X3,222,896 12/1965 Schneider 68-48 X 1,776,190 9/1930 Mishaw 68-201,865,218 6/1932 Spalding 68-18 1,985,376 12/ 1934 Lindenberger 8-1423,238,750 3/1966 Candor et al 68--20 WILLIAM I. PRICE, Primary Examiner.

US. Cl. X.R. 68-18

